New Delhi, Jan 24 : 10-time Australian Champion Novak Djokovic praised Indian veteran Rohan Bopanna who on Wednesday became the oldest World No. 1 men's doubles with his partner Matt Ebden, at the age of 43 when the latest ATP rankings update will be released on Monday after the conclusion of the grand slam tournament. Novak Djokovic praising the veteran wrote on Instagaram, 'Amazing effort. And to do it as such young age even more impressive.' The second-seed Indo-Aussie pair defeated the sixth-seed Argentine duo Maximo Gonzalez and Andres Molteni 6-4, 7-6 (7-5) at the Margret Court Arena to advance to semis of the Australian Open 2024. The quarterfinal win propels Bopanna ahead of the current World No. 1, USA's Austin Krajicek, in the ATP Rankings. Krajicek, alongside his Croatian partner Ivan Dodig, were bowed out in the second round. Bopanna and Ebden will next take on the Czech-Chinese pair of Tomas Machac and Zhizhen Zhang in the semifinals. Previously on Tuesday, Novak Djokovic, the defending champion, endured a four-hour test in the scorching Melbourne heat, eventually overcoming Taylor Fritz 7-6(3), 4-6, 6-2, 6-3. Djokovic's victory marked his 33rd consecutive Australian Open win, equalling Monica Seles's record, and secured his spot in a staggering 48th Grand Slam semifinal. /IANS